Apparatus particularly useful for chlorinating a reservoir

ABSTRACT

A long thin flexible teflon tube extending in a drain line of a reservoir from the point where the line opens into the bottom of the reservoir to a point outside the reservoir where the tube extends outside the drain line and is removably connected to a chlorine gas bottle, there being provided at the point where the tube is connected to the bottle a fixed metering port, and there being provided a protector tube surrounding the thin tube from the drain line to the chlorine bottle, and a gas diffuser connected to the end of said thin tube where it opens into the reservoir. A method of installing the above mentioned apparatus wherein one end of the thin tube is placed into the drain line at the bottom of the reservoir, and then, by drawing water from the reservoir through the drain line, the tube is drawn through the drain line to a point outside the reservoir, and then the tube is passed through a hole in the side of said line at a point outside the reservoir, then the tube is connected to a chlorine gas bottle.

United States Patent 1191 Morrison 1451 Sept. 25, 1973 APPARATUS PARTICULARLY USEFUL FOR CHLORINATING A RESERVOIR [76] Inventor: John M. Morrison, 11591 Cypress,

Orange, Calif. 92668 22 Filed: May 20,1971

21 Appl.No.: 145,233

Primary ExaminerMichael Rogers AttorneyNoel G. Conway [5 7 ABSTRACT A long thin flexible teflon tube extending in a drain line of a reservoir from the point where the line opens into the bottom of the reservoir to a point outside the reservoir where the tube extends outside the drain line and is removably connected to a chlorine gas bottle, there being provided at the point where the tube is connected to the bottle a fixed metering port, and there being provided a protector tube surrounding the thin tube from the drain line to the chlorine bottle, and a gas diffuser connected to the end of said thin tube where it opens into the reservoir.

A method of installing the above mentioned apparatus wherein one end of the thin tube is placed into the drain line at the bottom of the reservoir, and then, by drawing water from the reservoir through the drain line, the tube is drawn through the drain line to a point outside the reservoir, and then the tube is passed through a hole in the side of said line at a point outside the reservoir, then the tube is connected to a chlorine gas bottle.

12 Claims, 16 Drawing Figures 'PATENTEDSEP25I9?3 3,760,947

INVENTOR. J'aH/v M. Mome/sa/v ZW E8 FIG.9

APPARATUS PARTICULARLY USEFUL FOR CHLORINATING A RESERVOIR This invention relates to apparatus for treating liquid in a reservoir, and more specifically to apparatus particularly useful in chlorinating water in a swimming pool and a method of installation of such apparatus.

Although the present invention is useful in treating pools of water such as reservoirs, it finds its primary use in the field of chlorinating swimming pool water. Such bodies of water have to have chlorine added to them in order to prevent unwanted growth of algae and bacteria. In the past, such chlorine is added to the swimming pool water in the liquid form or the powder form. In each such case, there is the problem that large amounts of salts must be added to the material because of the characteristics of the chlorine. And, these salts hurt the eyes of the swimmers and pollute the swimming pool water. Furthermore, these systems are what might be called shock systems. That is, a large amount of the material is added to boost the chlorine content of the water (actually, one is increasing the percentage of I-IOCl). And then, the owner of the pool will wait until the chlorine content decreases to a certain predetermined'level before again placing an additional amount of material in the pool.

The adverse effect of the pollutants which must accompany commercially available liquid and powdered chlorine can be avoided by using chlorine gas directly. And, in the past, there has been suggested systems wherein chlorine gas is introduced directly into the swimming pool water. However, all of those are shock systems in that the chlorine gas is only injected at certain times. This requires complicated controls which are extremely. expensive to manufacture and maintain because of, among other things, the corrosive nature of chlorine.

Furthermore, I have found that a system which will continuously chlorinate the swimming pool water greatly reduces the amount of chlorine needed.

In the field of swimming pools, cost is extremely important. Accordingly, there is a need for low cost apparatus which can accomplish the control over the swimming pool. Furthermore, that apparatus must be capable of being installed at a low cost, and operated with a minimum of maintenance. In addition, the chemical used must not be prohibitively expensive. Embodiments of the present invention meet these requirements.

One aspect of the present invention is that, because of the particular features, the apparatus is extremely inexpensive to manufacture. Among other things, this is because there are no moving parts. In particular, the apparatus does not require a finely controlled valve.

Another aspect of the present invention is that it can be mounted'so as to produce the maximum efficiency. That is, the apparatus is installed in the-swimming pool to dispense the gas at the deepest portion thereof. Therefore, there will be the maximum exposure of the chlorine gas to the swimming pool water as the gas bubbles rise to the surface.

Still another aspect of the present invention is the particular gas diffuser which is incorporated therein, which gas diffuser can be manufactured at low cost, and yet, is not attacked by the chlorine gas involved.

A further aspect of the present invention is the manner in which the apparatus can be installed at the optimum position in the swimming pool, or reservoir. More particularly, a long thin flexible tube of the apparatus can have one end inserted in the drain line of the pool where the drain line opens into the deepest part of the pool. Then, a pump connected to the drain line draws water and the thin flexible tube into the drain line to a point outside of the pool. At that time, the thin tube can be passed through a hole in the wall of the drain line and have one end connected to the chlorine gas source while the other end of the thin tube has connected to it a gas diffuser located at the inlet to the drain line.

. With the foregoing in mind, it is a major object of this invention to provide improved apparatus for treating fluid in a pool such as a reservoir or swimming pool.

It is another object of this invention to provide improved apparatus for chlorinatingwater in a swimming pool.

It is still another object of this invention to provide improved apparatus for chlorinating swimming pool water, which apparatus can be manufactured at a very low cost, and is easily maintained.

It is a still further object of this invention to provide apparatus for chlorinating swimming pool water, which apparatus can be easily and rapidly installed in an existing swimming pool.

Another object of this invention is to provide apparatus for continuously chlorinating liquid in a reservoir.

It is still another object of this invention toprovide an improved method of installing in a reservoir apparatus for treating fluid into the reservoir.

A further object of this invention is to provide an improved method for installing apparatus for chlorinating water in a swimming pool.

A still further object of this invention'is to provide an improved gas diffuser for diffusing chlorine gas.

Another object of this invention is to provide an improved metering port for continuously permitting passage of small amounts of chlorine gas.

Other and further objects of this invention will become apparent in the detailed description below in conjunction with the attached drawings wherein:

FIG. 1 is a schematic view of a swimming pool with a perferred embodiment of apparatus of the present invention installed therein;

FIG. 2 is an enlarged fragmentary plan view of the gas diffuser of said apparatus mounted in the drain grate of the swimming pool;

FIG. 3 is an enlarged fragmentary cross sectional view of the gas difiuser taken along'line 3-3 in FIG.

FIG. 4 is a fragmentary elevational view of the upper portion of a chlorine gas bottle;

' FIG. 5 is an enlarged fragmentary cross sectional view of the outlet of the chlorine bottle, taken along line 5-5 in FIG. 4;

FIG. 6 is anenlarged cross sectional view of the filter of the apparatus, taken along line 6-6 in FIG. 5;

FIG. 7 is an enlarged fragmentary cross sectional view of a portion of the filter assembly, taken along line 7--7 of FIG. 5;

FIG. 8 is an enlarged fragmentary cross sectional view of the glass rod with the metering port of the apparatus;

FIG. 9 is an enlarged fragmentary cross sectional view of the lint pot, or strainer unit, of the system into which the apparatus is installed;

FIG. is a schematic view of the swimming pool at an initial stage of a preferred method of installing the apparatus in a swimming pool;

FIG. 11 is an enlarged fragmentary cross sectional view of the entrance to the drain line disclosing in further detail a portion of the apparatus used in installing the apparatus;

FIG. 12 is an enlarged fragmentary cross sectional view disclosing details of the connector which connects a leader to the thin flexible tube during the installation method;

FIG. 13 is an enlarged fragmentary cross sectional view disclosing the manner in which a hook is inserted through the side of the drain line to hook the leader during the installation method;

FIG. 14 is an enlarged fragmentary cross sectional view of the drain line disclosing how the leader connected to the thin flexible tube is drawn out through a hole in the side of the drain line;

FIG. 15 is an enlarged fragmentary partial cross sectional view disclosing the manner in which a protector tube is mounted to the drain line, which protector tube protects the thin flexible tube from the drain line to the chlorine bottle; and,

FIG. 16 is an enlarged fragmentary partial cross sectional view of the apparatus disclosed in FIG. 15 but with the protector tube in a slightly different position.

Referring now to FIGS. 1 through 9, a preferred form of the apparatus incorporating the present invention will be described in detail. In FIG. 1, .there is shown a swimming pool, indicated generally by the arrow 10. As is normal, the swimming pool 10 has a drain line 11 which opens into the lowest portion of the pool, and is connected to a lint pot, or strainer unit, 12 at a location outside of the pool, e.g., on the deck adjacent the swimming pool. The outlet of the strainer unit 12 is typically connected to a pump 14, which in turn, is connected to a filter 13. The outlet of the filter 13 is typically connected back to the swimming pool through a return line 15 (directly or after passing through a heater).

It is to be understood that the drain line 11, strainer unit 12, filter 13, pump 14, and return line 15 are merely for illustrative purposes. In regular swimming pool units, there are oftentimes piping and valving involved. For example, water from the skimmer is also fed into the filter unit.

As shown in FIG. 1, the apparatus includes a chlorine gas bottle 20 from which gas is continuously injected into the swimming pool water as will be described further below. For the purposes described below, there is a protector tube 22 extending from the drain line 11 to the gas bottle 20.

As will be described further below, gas from the bottle 20 is fed to a diffuser 23 mounted at the bottom of the swimming pool 10, and accordingly, there will be a continuous stream of minute bubbles 24 purifying the swimming pool water all of the time that the gas is turned on at the bottle 20.

Referring now to FIGS. 2 and 3 in particular, a preferred form of the gas diffuser will be described in detail. There it can be seen that pool bottom 25 has a drain plate, or grate, 26, received at the inlet of the drain line 11. Typically, the drain grate 26 may be made up of plastic, and has a large number of holes 27 through which water may be drawn from the swimming pool into the drain line 11.

The diffuser 23 comprises a first member 28 which is threaded at its upper end (as seen in FIG. 3), and threadedly receives thereon collar 29, havinga discharge opening 30 therethrough. Extending across the opening 30 is a glass fritted disc 31, which comprises a very large number of extremely small glass beads which are joined together. The openings in the disc 31 are preferably in the order of 5 microns. In order to seal the disc 31 and hold it in position, an O-ring 32 is provided on either side of the disc. Thereby, rotation of the collar 29 efiects a seal between the member 28 and the disc 31 by means of the lower O-ring 32.

For purposes of wily anchoring the diffuser 23 to the drain grate 26, there is provided a depending threaded boss 34 which is received into threaded hole 35 at, preferably, the center of the drain grate 26. It should be noted how easily the diffuser 23 can be installed in the standard drain grate 26. The installer need merely drill the hole 35 to the proper size and thread it. And then, he merely screws the diffuser 23 into operating position.

As is known, the hydrochloric acid (formed by the water and the chlorine gas) is quite corrosive. Therefore, there is the problem of providing a diffuser unit 23 of a material, or materials, which is not attacked by such acid, or the chlorine gas. It has been found that a diffuser unit 23, made with the member 28 out of PVC and the collar 29 out of ABSI and the O-rings 32 out of ethylene propylene, works well and can be made without undue expense. Naturally, teflon could be substituted-or the other materials just mentioned could be substituted for each other-in the manufacture of the member 28, the collar 29, and the O-rings 32.

The drain line 11 of the swimming pool 10 is also susceptible to being attacked by the chlorine gas if the gas were permitted to be in the line. Furthermore, the drain line 11 (and the drain lines of different swimming pools, or reservoirs), have many different turns. Therefore, in order to conduct gas from the chlorine bottle 20 to the diffuser 23, and yet accommodate the many turns of the drain line 11, there is provided a long thin flexible tube 36. This flexible tube 36 is preferably made of teflon approximately one-eighth inch CD. This size tube will carry more than enough chlorine gas (because the chlorination process is continuously being done), and is quite flexible. Furthermore, the very thin tube 36 greatly reduces the cost of the apparatus as teflon is sold essentially on the basis of weight.

The teflon tube 36 has a small amount of give to it. Therefore, it can be installed in the first member 28 in the following manner. Firstly, the tube 36 is cut on a slant. Then, the tube 36 is forced through hole 37 in the member 28, which hole is only slightly smaller than the CD. of the tube 36. Because of the cut at an angle, the tube 36 can be pushed through the hole 37 sufficiently so that the tube can be gripped. Then, the tube 36 is pulled on through the hole 37 and cut off substantially to the condition shown in FIG. 3. The friction fit between the tube 36 and the wall of the hole 37 effects a sufficient seal.

It should be noted that the discharge opening 30 is many times larger than the opening of the tube 36. Therefore, the gas passes through the disc 31 at a very low velocity.

The tube 36 extends through the drain line 11 and the protector tube 22 in a manner to be described in further detail below. At this time, it is desired to explain in further detail a preferred form of connecting the tube 36 to the bottle and providing an economical filter and metering port.

Referring now to FIGS. 4 and 5, the bottle 20 has a standard fitting 38 at the upper end thereof which has therein a manually controlled valve (not shown), which can be opened and closed by rotating removable handle 38a. As seen in FIG. 5, the fitting 38 has a partition 39 with an outlet hole 40 therethrough.

It is desired that the chlorine gas be filtered in order to eliminate the possibility of a piece of metal or dirt from the valve clogging critical portions of the apparatus. To this end, there is provided a teflon cloth 4] which extends across .the upstream end of split teflon sleeve 42 and is held between said sleeve and the wall of the hole 40.

It should be noted how quickly the filter of the teflon cloth 41 can be installed into the hole 40 which is a standard size hole in the standard fitting 38 of a standard chlorine gas bottle 20. The installer merely spreads the teflon cloth 41 across the downstream end of the hole 40 (on the left as seen in FIG. 5). Then, he compresses the split ring 42 slightly so as to start it into the hole 40 (with the cloth 42 between the ring andthe wall of the hole). Then, he merely pushes the split ring 42 (with the cloth 41) into the position shown in FIGS. 5, 6, and 7. The spring tension of the teflon sleeve 42 will hold the cloth 41 in position.

At the discharge mouth of the fitting 38, there is provided a mounting flange 44 (preferably made of teflon) which is removably sealed and anchored to the fitting mouth by means of a threaded collar 45. The flange 44 has a bore 46 through the main body thereof. 0

At the upstream side of the flange 44, there is provided a teflon bushing 47 received in the bore 46. The bushing 47 has a glass. rod 48 through the center thereof. And, the glass rod 48 has a minute passageway 49 therethrough along the axis thereof. (Teflon cannot be used as it cold flows and will not hold proper size.) The glass rod 48 is held in the bushing 47 by a press fit. And, the bushing 47 and mounting flange 44 are provided with pipe threads so that the bushing will seal to the mounting flange when tightened into the bore 46.

By the above arrangement, an effective seal can be accomplished, and all chlorine gas must pass through the minute passageway 49. -Yet, if the passage 49 is blocked, or a difierent passage is desired, another glass rod can be quickly substituted by merely unthreading the bushing 47 and inserting a new bushing having a glass rod with a passage therethrough. This lessens the cost of inventory (since the same size tube 36 can be used for a wide range of passages 49), and minimizes the cost of maintenance.

The size of the passage 49 depends upon the sought after rate of gas flow into the swimming pool, I have found that (with thegas bottle 20at normal temperatures, a passage of approximately 0.0015 inch in diameter to 0.0025 inch is quite suitable for an average size home swimming pool (approximately 20,000 gallons with approximately 650 square feet of surface area).

The end of the tube 36 opposite the end connected to the diffuser 23 is connected to a bushing 51 in the same manner as said opposite end of the tube is connected to the first member 28. Therefore, a seal can be accomplished between the outside of the tube 36 and the bore of the bushing 51. Then, through the use of pipe threads, the bushing 51 can be sealed to the mounting flange 44.

As is obvious, the teflon tube 36 can be quite easily damaged. Therefore, there is preferably provided tube shielding means enclosing the flexible tube 36 from the drain line 11 to the mounting flange 41. Said shield means preferably takes the form of protector tube 22 (preferably made out of copper) which is flared at the end abutting the mounting flange 44 and held by a flared tube fitting collar 52.

There should be provided mounting means for connecting the protector tube 22 to the drain line 11. A preferred form of such means is disclosed in FIGS. 15 and 16. There, it can be seen that a hole 53 has been provided in the side of the drain line 11 at a selected point outside of the pool 10. The tube 36 has been previously passed up through the center of the protector tube 22 and is sealed to the protector tube by means of a plug 54 having a hole through the center thereof. Said 7 plug 54 may have a split through one side in order that 'the slit.

A mounting bracket 55 partially encircles the drain line 11 and is removably held to said drain line through the use of an adjustable strip 56 which passes the rest of the way around the drain line. Said mounting bracket 55 has a hole through the center thereof through which is received-an upstanding sleeve 57. As can be seen, the sleeve 57 is pulled by the mounting bracket 55 to squeeze O-ring 58 tightly against the outer surface of the protector tube 22 to seal the drain line 11 at the'hole 53. The lower end of the sleeve 57 is shaped to conform to the exterior of the drain line 11.

In order to selectively clamp the protector tube 22 in the desired position, there is provided a tapered split sleeve 59 between the upstandingsleeve 57 and the tube 22. Then, by merely tightening threaded collar 60, the tapered split sleeve 59 can clamp radially inward against the protector tube 22 and anchor it to the sleeve 57. This arrangement allows precise adjustment of the protector tube 22 to minimize the requirement to move the gas bottle 20. As can be seen in FIG. 16, the protector tube 22 can be secured with more of it projecting into the drainline I1.

Referring now to FIGS. 10 to 14, a preferred method of installing the apparatus will be described. In FIG. 10, there is shown a supply reel 63 from whichthe tube 36 is fed. For a purpose to be described below, a leader 64 of approximately 10 to 12 feet in length is connected to the end of the tube 36 by means of a connector 65. Asbest seen in FIGS. 9 and 11, there is a ball 66 connected to the end of the leader 64 opposite the connector 65. The leader 64 is preferably the same size teflon tubing as the tube 36. Therefore, the leader 64 can be easily connected to the connector 65 by means of a taperedplug 67 as seen in FIG. 12. The outside of the connector 65 is tapered as shown to minimize the changes of the connector catching or hanging up as it is pulled through the drain line 11 or the. hole 53.

The ball 66 is preferably of hard rubber and significantly heavier than .water. Therefore, it will sink, carrying the leader 64 and the tube 36 with it. Said ball 66 is slightly smaller than the drain line 11.

In the installation process, the installer first removes the drain grate of the pool and positions the ball 66 at the position shown in FIG. 11. At that time (or previously), the installer turns the pump 14 on such as to draw water from the swimming pool 10 into the drain line 1 1. That water will pull the ball 66, and therefore, the leader 64 and tube 36 into and through the drain line 11 until the ball goes into lint pot l2 and is caught in basket 68 of the lint pot. (See FIG. 9). The installer will know that the ball 66 is in the basket 68 by several reasons. Firstly, he can determine how much tube 36 has been fed into the drain line 11. Also, when the ball 66 reaches the strainer 68, there will be greatly less pull on the tube 36 even though the pump 14 continues to run.

The tube 36 must get from the interior of the drain line 1 1 at a point outside of the swimming pool 10. To this end, a hole 53 (see FIGS. 13 and 14 in particular) is drilled into the side of the drain line. When the hole 53 is located in the drain line as shown, a hook 71 is used to reach into the drain line and hook the leader 64 and pull it out of the drain line through the hole 53 as shown in FIGS. 13 and 14. After the connection 65 is pulled through the hole 53, the bushing 51 is unthreaded from the connector. Then, the connector 65 is pushed back through the hole. At that time, the ball 66, leader 64, and connector 65 can be removed through the top of the lint pot 12 after removal of the lid 69.

The installation method then continues with the above mentioned plug 54 being placed around the tube 36, and the tube 36 being passed through the center of the protector tube 22. Then, the bushing 51 can be threaded into the mounting flange 44 (the mounting flange 44 having been previously mounted to the fitting 38). And then, collar 52 is used to secure the protector tube 22 to the mounting flange 44.

It is to be noted that the leader 64 has several useful functions. Firstly, the leader 64 is hooked with the hook 71 and pulled through the hole 53 in the folded condition (see FIGS. 13 and 14) rather than the tube 36 which is to be used permanently. If any crimping or pinching occurs during this process, it will happen to the leader 54 and not damage the tube 36.

Secondly, it is preferred that the diffuser 23 and the bushing 51 can be attached to the tube 36 at the factory after the tube 36 has been cut to the desired length. The tube 36 is cut to the desired length after estimating at the job site the amount to tube needed. Then, the tube 36 (with the bushing 51 and the diffuser 23 attached) is taken to the job site. This system has the advantage that it is much easier to connect the diffuser 23 and the bushing 51 with the tools available at the factory. Further, one person can make up tubes with bushings and diffusers connected for several installers. Therefore, this system permits specialization.

When the tube 36 (with the bushing 51 and diffuser 23 attached) it is taken to the, job site and being installed, the installerbecause of the extra length of the leader permits the installer to hold on to the tube 36 during the entire time that the tube is being fed through the drain line 11. More particularly, the leader 64 is long enough to reach from the entrance to the drain line 11 up to the deck where the installer is standing. Therefore, the ball 66 will reach the lint pot 12 just before the installer would have to let go of the diffuser 23 (which would have previously been connected to the drain grate 26). It is desired that the installer keep a hold on the tube 36 during the time that it is being drawn through the drain line 11 because of the following reason, among others. If the ball 66 gets stuck in the line somewhere, it can be freed by pulling it back against the current of the water.

From the foregoing, it can be seen that the apparatus can be very quickly installed in existing swimming pools with only minor modifications, i.e., a threaded hole in the drain grate 26 and a hole in the drain line 11. This is extremely important.

Another aspect of the present invention is that it permits the chlorine in the water to be maintained at a lower level than the shock systems. This is because the gas is continuously being dispersed into the water day and night. And, it has been found that the system will work satisfactorily, i.e, there is no algae or bacteria growth when the chlorine level is down around 0.2 ppm, whereas, in a shock system, the chlorine must be raised considerably above that so that the chlorine wont drop below around 0.2 ppm before the next shock of chlorine. This is important because reducing the amount of chorine reduces the amount of soda ash that you have to put into the water. And, that soda ash pollutes the water.

It should also be noted how the apparatus automatically compensates for the ambient conditions. As is known, the sunlight shining down on the pool destroys the chlorine more rapidly than when there is no sunlight. Therefore, it is desired that there be more chlorine ejected during the times when the sun shines and less during the night when there is no sunshine. This requirement is accommodated because the sunshine causes extra heat. This heats the bottle 20 and increases the pressure within the bottle 20, thus increasing the flow through the metering port of the passage 49.

While only a few embodiments of the present invention have been shown and described in detail, it will be apparent to those skilled in the art that such is by way of illustration only and numerous changes may be made thereto without departing from the spirit of the present invention. Accordingly, it is my intention that the invention be limited solely by the appended claims.

I claim:

1. In an apparatus particularly adapted to chlorinate continuously swimming pool water in a swimming pool having a drain pipe which opens into the pool through an inlet port:

a source of chlorine gas having an outlet-port;

a long thin flexible plastic tube having a first and a second end;

mounting means on said first end for connecting said first end to said outlet port;

a metering port at said first end for metering gas entering said tubing from said outlet port, said metering port having an orifice passage of diameter substantially smaller than the inside diameter of said tubing;

and means at said second end of said tubing for preventing said second end from entering the inlet port of the drain pipe 2. The invention set forth in claim 1 including:

difl user means connected to said second end of said tube for diffusing gas exiting said tubing into minute bubbles.

3. The invention set forth in claim 2 wherein said diffuser means includes:

a housing having a cavity therein with a discharge opening substantially larger than the tube;

and a porous plate sealed to said housing across said discharge opening.

4. The invention set forth in claim 2 wherein:

the diffuser means is attached to be used at the inlet of a drain pipe in the bottom of the pool, and said diffuser means includes: retainer means for preventing said diffuser means from entering said drain pipe.

5. In combination with a reservoir pool having a drain pipe which communicates the bottom of the pool with a pump, said drain pipe having means forming an upwardly facing inlet port located at a deep portion of the pool, a system for continuously chlorinating water in said pool, said system comprising:

a source of chlorine 'gas having an outlet port;

a long thin flexible tube having a first end connected to said chlorine gas source and a second end, said tube extending through said drain pipe with said second end opening at the inlet port forming means of said drain pipe so that gases emitting from the tube will not be emitted into water within the drain pipe. I

6.- The invention set forth in claim, 5 including:

a grate across the inlet port of said drain pipe;

and diffuser means connected to the second end of said tubing for diffusing gasexiting said tubing into minute bubbles, said diffuser means being anchored to said grate.

7. The invention set forth in claim 5 wherein:

said chlorine gas source is located adjacent said drain pipe and has an outlet port;

said flexible tube extends from said source outlet port through a hole in the wall of said drain pipe into said drain pipe;

and there is provided tube shielding means enclosing said flexible tube from said drain pipe at said hole to said vsource outlet port, said tube shielding means comprising: I g a protector tube of relatively hard material as compared to said flexible tube; connector means connecting a first end of said protector tube to said outlet port of said source; mounting means at a second end of said protector tube, said mounting means providing a seal between the wall of said drain pipe around said hole and said protector tubing.

8. The invention set forth in claim 7 wherein said metering port is formed by a rod with minute passage therethrough said connector means comprises:

a bushing having a central hole therethrough;

means sealing said bushing to said outlet port;

means connecting said protector tube to said bushing;

means sealing said rod in said hole in said bushing;

and means sealing said flexible tube to said hole in said bushing.

9. The invention set forth in claim 7 wherein said mounting means comprises:

anchor means for securing said mounting means to said drain pipe at said hole in said drain pipe wall;

a sleeve having a central bore receiving said second end of said protector tube at least partway through said bore; I

and means on said sleeve for adjustably connecting said protector tube to said sleeve.

10. The invention set forth in claim 7 including:

means at the second end of said protector tube for sealing said flexible tubing to said protector tube.

1 1. In a system for continuously chlorinating water in a pool, which pool has a pipe which extends from a first point outside of the pool to a second point in the structure of the pool below the normal water line of the pool, said pipe having means forming aport at said second point opening into said pool;

a source of chlorine gas near said first point;

a long thin flexible tube having a first end and a second end, said tube extending through said pipe from said'first point to said port, said first end of said tube being connected to said gas source whereby gas may be supplied into the tube;

exit means at the second end of said tube forming an outlet to permit gas within the tube to exit the tube, said exit means being positioned at least partially out of said pipe into said pool so that bubbles exiting the tube will exit into the water in the pool and not the water in the pipe.

12. The combination set forth in claim 11 wherein said exit means comprises:

diffuser means for diffusing gas exiting the tubing into minute bubbles. 

1. In an apparatus particularly adapted to chlorinate continuously swimming pool water in a swimming pool having a drain pipe which opens into the pool throUgh an inlet port: a source of chlorine gas having an outlet port; a long thin flexible plastic tube having a first and a second end; mounting means on said first end for connecting said first end to said outlet port; a metering port at said first end for metering gas entering said tubing from said outlet port, said metering port having an orifice passage of diameter substantially smaller than the inside diameter of said tubing; and means at said second end of said tubing for preventing said second end from entering the inlet port of the drain pipe
 2. The invention set forth in claim 1 including: diffuser means connected to said second end of said tube for diffusing gas exiting said tubing into minute bubbles.
 3. The invention set forth in claim 2 wherein said diffuser means includes: a housing having a cavity therein with a discharge opening substantially larger than the tube; and a porous plate sealed to said housing across said discharge opening.
 4. The invention set forth in claim 2 wherein: the diffuser means is attached to be used at the inlet of a drain pipe in the bottom of the pool, and said diffuser means includes: retainer means for preventing said diffuser means from entering said drain pipe.
 5. In combination with a reservoir pool having a drain pipe which communicates the bottom of the pool with a pump, said drain pipe having means forming an upwardly facing inlet port located at a deep portion of the pool, a system for continuously chlorinating water in said pool, said system comprising: a source of chlorine gas having an outlet port; a long thin flexible tube having a first end connected to said chlorine gas source and a second end, said tube extending through said drain pipe with said second end opening at the inlet port forming means of said drain pipe so that gases emitting from the tube will not be emitted into water within the drain pipe.
 6. The invention set forth in claim 5 including: a grate across the inlet port of said drain pipe; and diffuser means connected to the second end of said tubing for diffusing gas exiting said tubing into minute bubbles, said diffuser means being anchored to said grate.
 7. The invention set forth in claim 5 wherein: said chlorine gas source is located adjacent said drain pipe and has an outlet port; said flexible tube extends from said source outlet port through a hole in the wall of said drain pipe into said drain pipe; and there is provided tube shielding means enclosing said flexible tube from said drain pipe at said hole to said source outlet port, said tube shielding means comprising: a protector tube of relatively hard material as compared to said flexible tube; connector means connecting a first end of said protector tube to said outlet port of said source; mounting means at a second end of said protector tube, said mounting means providing a seal between the wall of said drain pipe around said hole and said protector tubing.
 8. The invention set forth in claim 7 wherein said metering port is formed by a rod with minute passage therethrough said connector means comprises: a bushing having a central hole therethrough; means sealing said bushing to said outlet port; means connecting said protector tube to said bushing; means sealing said rod in said hole in said bushing; and means sealing said flexible tube to said hole in said bushing.
 9. The invention set forth in claim 7 wherein said mounting means comprises: anchor means for securing said mounting means to said drain pipe at said hole in said drain pipe wall; a sleeve having a central bore receiving said second end of said protector tube at least partway through said bore; and means on said sleeve for adjustably connecting said protector tube to said sleeve.
 10. The invention set forth in claim 7 including: means at the second end of said protector tube for sealing said flexible Tubing to said protector tube.
 11. In a system for continuously chlorinating water in a pool, which pool has a pipe which extends from a first point outside of the pool to a second point in the structure of the pool below the normal water line of the pool, said pipe having means forming a port at said second point opening into said pool: a source of chlorine gas near said first point; a long thin flexible tube having a first end and a second end, said tube extending through said pipe from said first point to said port, said first end of said tube being connected to said gas source whereby gas may be supplied into the tube; exit means at the second end of said tube forming an outlet to permit gas within the tube to exit the tube, said exit means being positioned at least partially out of said pipe into said pool so that bubbles exiting the tube will exit into the water in the pool and not the water in the pipe.
 12. The combination set forth in claim 11 wherein said exit means comprises: diffuser means for diffusing gas exiting the tubing into minute bubbles. 